concerned with the hardships and dangers of military life. Another poet and member of the Polish Brethren, Wacław Potocki, converted to Catholicism. His poetry depicts the life of Polish landed gentry and historic events. He wrote the epic poem The Conduct of the Khotyn War (of 1621) and was deeply troubled by the social injustice in the Commonwealth and its decline. The szlachta apologist Wespazjan Kochowski expressed no such misgivings, but even he could not conceal the progressive degeneration of his class. In the era of constant warfare the writing of memoirs had become an often practiced art. Jan Chryzostom Pasek was one of the leading in Europe representatives of this genre. Macaronic language, Polish mingled with Latin, was frequently used in writing. The mid 18th century movement to clear Polish from the Latin admixture was led by Stanisław Konarski and Franciszek Bohomolec. Royal court theater continued under John Casimir, John III, August II and August III. Foreign troupes were brought from Italy (Italian repertoire was the most popular), France and Germany. At least ten magnate-supported theaters functioned in Saxon times, including one at the Ujazdów Castle, where Stanisław Lubomirski staged his comedies, and one at Podhorce, where the historic plays of Hetman Wacław Rzewuski were being shown. School theaters were maintained by the Jesuits, Piarists and Theatines and there were religious spectacles for the general public, including mystery plays, passions and nativity scenes, typically with folk elements. Music served mostly the needs of the Church and had remained under primarily Italian influence. Pipe organs were brought from abroad and constructed locally; the instrument built in 1682 in Leżajsk is of the highest quality. Many instrumental and vocal ensembles were active at various church institutions. Bartłomiej Pękiel composed polyphonic music including a cappella masses and the first in Poland cantatas. Stanisław Sylwester Szarzyński wrote instrumental music of which only one sonata has survived. Secular (court bands) and folk music was also practiced and the mazurka folk dance crystallized during that period. Foreign operas and ballets were staged in Warsaw under Augustus II and Augustus III. The finest artistic manifestation of the Baroque in Poland is its architecture, developed under the Italian, Dutch, German and French influence, with a strong local component. The new elaborate residential and religious compounds, or the rebuilding of older, war-damaged structures, were financed by magnates and the Church. St. Peter and St. Paul's Church in Vilnius